Police said Saturday they had arrested 142 people in a two-day anti-terrorism security sweep around Milan prompted by the bombings two days earlier in London.

Some 2,000 carabinieri fanned out across the Lombardy region, stepping up patrols around train stations, subways, commercial centers and other sensitive sites, the regional commander of the paramilitary police, Gen. Antonio Girone (search), said in a phone interview.

Girone said the operation was focusing on Milan because it had been the major focus of Italian investigations into Islamic terrorism and because it "could be a major risk of possible attacks." He said the measures were designed to make people "feel calmer after the London attacks."

Of those arrested, 84 were immigrants and authorities issued 52 expulsion orders, he said. Most of those arrested were accused on drug, petty theft or immigration-related charges, he said.

The operation was one of the most visible signs of stepped up security measures around Italy following Thursday's attacks in London and threats that Italy might be targeted as well for its support of the U.S.-led wars in Iraq and Afghanistan.

The Interior Ministry said it was stepping up police and intelligence controls around the country, and in particular around sites most at risk of terrorist attack.

British installations in Italy were the top priorities. But some 13,246 sites around the country — including U.S. and NATO bases (search), telecommunications centers, public utilities and the Turin 2006 Winter Olympics (search) site — also were under special surveillance and had been since the beginning of the year, the ministry said.

The ministry also said it was looking into possible new emergency legislation to deal with the terrorist risk. It didn't elaborate.

The new measures came after a group calling itself "The Secret Organization of al-Qaida in Europe" said the bombings were punishment for British involvement in the U.S.-led wars in Iraq and Afghanistan and said Italy and Denmark would be attacked for their support of the U.S.-led coalitions in both countries, too.

Premier Silvio Berlusconi said Friday that Italy would begin withdrawing 300 troops from Italy's 3,000-strong contingent in Iraq, but denied the withdrawal was linked to any terrorist threats against Italy. He had previously said he hoped to begin withdrawing troops by September, though officials later pushed the date back to early 2006.

Berlusconi is a staunch ally of President Bush (search) and sent about 3,000 troops to Iraq after the fall of Saddam Hussein (search) to help rebuild the country. Italy also has about 910 troops in Afghanistan.